Radiolucent Patient Treatment Table with Removable Tip Extension Base and Accessories

ABSTRACT

The present invention provides a radiolucent patient treatment table top with a removable tip extension base that can be accurately and repeatably mounted at the end of a table top that is completely metal free in the area of interest for imaging and treatment. The table top is composed primarily of polymer composites reinforced with carbon fibers or other non-metallic fibers such as Kevlar®. The table top allows for accurately and repeatably mounting removable tip extension members, radiographic phantoms, immobilization devices, brachytherapy steppers, and other devices to the end and sides of the patient table top. The present invention further provides a method of adding a variety of useful accessories without introducing any permanent metal components in the imaging/treatment area of the table top.

This application claims the benefit of U.S. Provisional Application60/782,033 filed 14 Mar. 2006, entitled “Radiolucent Patent TreatmentTable with Removable Tip Extension Base and Accessories.”

BACKGROUND OF THE INVENTION

In modern medical procedures that require both imaging and treatment byx-rays, it is desirable to have a patient table top (also referred to asa couch top) that is transparent to x-radiation. The advent of Cone BeamCT has made it increasingly important that performance of the table topduring x-ray imaging be properly taken in to account. Any metal in theCT slice can cause artifacting which reduces image quality and caninterfere with calculations that are used to determine the optimumpatient radiation dosage. Examples of equipment capable of X-ray andCone Beam CT application on radiation therapy equipment include VarianMedical System's On Board Imager (OBI) and Elekta's XVI system.

Traditionally, radiation therapy table tops have been made from metal.Up until now, incorporating metal was necessary in order to carry theweight of the patient. Newer radiation therapy treatment table topsgenerally have metal free imaging and treatment sections, but contain anintegral metal tip extension base for attaching extensions andaccessories. This “universal tip” is used for certain procedures, but isnot required for others. Since it is a permanent part of the table top,it interferes with imaging and treatment at the tip of the table top. Itwould thus be preferable for this tip to be removable so that it is onlyattached to the table top when needed. One manufacturer includes aremovable tip extension, however, the attachment method of this tipextension (the Medical Intelligence I-beam™ table top) base requiresthat metal be permanently built in to the tip of the table top. Thisembedded metal interferes with both imaging and treatment radiation.

Brachytherapy and urological procedures often require attachingaccessories to the tip of the patient table top. These include itemssuch a stirrups to hold the patients legs and the stepper devices thatare used to aim and insert the catheters through which the radioactiveseeds are delivered. Traditionally, only static x-rays were taken duringthese procedures. However, once again, the advent of modem 3D imagingtechniques such as Cone Beam CT has made it possible to acquire a threedimensional understanding of the position of the organ of interest andthe device or devices that are being used to treat the patient. ThroughDICOM, the data from these images can be input into treatment planningsoftware so that improved treatment delivery can be achieved. All ofthis makes it desirable to be able to take metal free images through theentire table top.

SUMMARY OF THE INVENTION

The present invention addresses the above limitations in the prior artand provides a removable tip extension base that can be accurately andrepeatably mounted at the end of a table top that is completely metalfree in the area of interest for imaging and treatment. The table top iscomposed primarily of polymer composites reinforced with carbon fibersor other non-metallic fibers such as Kevlar®. The table top allows foraccurately and repeatably mounting of removable tip extension members,radiographic phantoms, immobilization devices, brachytherapy steppers,and other devices to the end and sides of the patient table top.However, when the accessories are removed, the result is a completelymetal free table top. This improves imaging performance and inparticular it improves performance with the new Cone Beam CTtechnologies that are becoming more prevalent on c-arms and high-energyradiation treatment (Radiation Therapy) machines. In addition, tipextensions of specific function can also be produced this way.

Specifically, the present invention provides a radiolucent patient tabletop system comprising a patient table with a front, an underside, atleast one side and a mounting support structure and further comprising;

-   -   a. a section which is completely metal free beyond the mounting        support structure;    -   b. the section capable of receiving removable accessories; and    -   c. a removable tip extension base wherein the tip extension base        provides a universal attachment mechanism which allows one or        more accessories to be attached to the table.

The present invention further provides a radiolucent patient table withat least one support beam and comprising a removable tip extension basethat has a back face and is attached to the patient table and whereinthe tip extension base provides a universal attachment mechanism forattaching one or more accessories to the table.

The present invention also provides a removable modular clamp comprisingan upper body, a lower body and a modular center section.

In another embodiment, the present invention provides a method ofperforming brachytherapy treatment procedures using a table top of thepresent invention comprising;

-   -   a. placing legs of a patient in radiolucent stirrups;    -   b. planning imaging and treatment;    -   c. placing a brachytherapy aiming stepper device at the end of        the table top;    -   d. inserting a cannula (i) into the patient;    -   e. removing the brachytherapy stepper device; and    -   f. imaging and treating the patient with radiation.

In yet another embodiment, the present invention provides a method oftreating a patient's head, neck or abdomen with external beam radiationtherapy using a table top of the present invention comprising;

-   -   a. attaching a tip extension base to a tip of the table top;    -   b. attaching an extension to the tip extension base to increase        the length of the table top;    -   c. placing a patient on the table top and locating the patient's        abdomen over the radiolucent table top; and    -   d. treating the patient.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a patient table top of the present invention.

FIG. 2 is an underside view of a table top of the present invention.

FIG. 3 illustrates a removable tip extension base of the presentinvention.

FIG. 4 illustrates a tip extension base of the present inventionattached to a table top.

FIG. 5 illustrates a QA phantom accessory attached to a tip extensionbase that is attached to a table top.

FIG. 6 illustrates a table extension accessory attached to a tipextension base that is attached to a table top.

FIG. 7 illustrates a drop leaf extension accessory attached to a tabletop.

FIG. 8 illustrates a brachytherapy stepper assembly accessory attachedto a table top.

FIG. 9 illustrates a removable modular clamp of the present invention.

FIG. 10 illustrates a removable modular clamp of the present invention.

FIGS. 11A and 11B illustrate a removable modular clamp of the presentinvention in a locked and unlocked position indexed to a table top.

FIGS. 12A-12D illustrate removable modular clamps of the presentinvention.

FIG. 13 illustrates a table top of the present invention with recessededges.

FIG. 14A illustrates a table top with support beams

FIG. 14B illustrates a sliding beam clamp attached to a tip extensionbase.

FIG. 14C illustrates a cross-section of a beam and removable clamp.

DETAILED DESCRIPTION OF THE INVENTION

The present invention is based on clamping the tip extension to thesides of the table top. This clamping method is unique because it allowsextremely high tip loads to be absorbed by the table top. Since theclamps attach to a section of the side of the table top, a large momentload can be reacted. In order to accurately and repeatably mount to thetable top, the present invention provides a male and female matingfeature along the front edge of the table top. This locates the TipExtension Base from side to side and can also be used to locate the TipExtension Base front to back and up and down (X, Y and Z coordinates).Alternatively, the surfaces (top, bottom, front and sides) of the tabletop can be used to locate the Tip Extension Base.

In a preferred embodiment, a groove or bump runs down the length ofeither side of the table top to allow the clamps a feature to lock onto, making it harder to dislodge that clamp once it is tightened. Byplacing indexing features down the length of either side of the couchtop, the clamps can be located at a specific longitudinal coordinate.Clamps can be designed so that they can be placed at these discreetlocations, located continuously along the length. In order to locate theclamp at the indexing features, the clamp can contain the matingfeature, spring loaded pins or other methods of ensuring that the clampis accurately located. In addition, clamps can be designed so that oneclamp can be used in either manner. By producing a modular clamp, avariety of additional accessories can be developed, in addition to theavailable specific devices and the tip extension base. This clamp isproduced in sections so that common parts become the building blocks forother accessories.

It is desirable that table tops designed for medical applications to befree of features on their top surface that could collect fluids. In apreferred embodiment, a clamp groove is placed longitudinally downeither side of the bottom of the table top. This provides a feature thatcan be grabbed by a clamp but does not present a fluid gathering site.

Although we have shown a flat upper surface in most of the accompanyingfigures, this means that the top of the clamp rises above the top planeof the table top. This can become an obstruction in cases whereadditional devices may need to be placed on the top surface of the tabletop. In a preferred embodiment, the edges of the table top can berecessed either locally or completely along each edge so that the top ofthe clamp is flush or slightly below the top surface of the table top.

A table top of the instant invention provides a particularly goodplatform for modern brachytherapy that is coupled with C-arm or ConeBeam CT technology. A new methodology for imaging and treating thepatient in which minimal movement of the patient is required is possiblewith the present invention. This is particularly important inbrachytherapy because imaging of the patient commonly occurs after thedelivery needles have been inserted into sensitive areas such as theperineum. Moving the patient at this time can be quite risky. An exampleof the methodology applied to gynecological or prostrate procedures thatcan now be followed is to:

1) Attach a drop leaf tip extension (leg support board) to the tip ofthe table top which allows the patient's legs to be rotated tohorizontal. The leaf is initially placed in the down or verticalposition so that the patient can easily sit at the tip of the table top.

2) The patient then lies back on the table top and the drop leafextension is rotated to horizontal. Thereby, placing the patient in thehorizontal position.

3) Stirrups may then be attached and the patient's legs are then placedup in the stirrups. The drop leaf tip extension can now be removed,leaving the lower abdomen area free for imaging studies. By usingradiolucent composite stirrups we are able to image through them,including when using Cone Beam CT. Imaging may take place at this time.

4) The brachytherapy stepper (aiming device) can be attached in place ofthe drop leaf tip extension. At this point, insertion of cannula (i) orcatheter can take place. By removing the stepper, one can now takeimages and Cone Beam CT studies without moving the patientlongitudinally down the table top because there is not metal or otherartifacting features present at the tip of the table top.

5) Once the medical staff are confident of the treatment plan andpositioning of the cannula (i) or catheter, treatment can commence.

The present invention provides a method of adding a variety of usefulaccessories without introducing any permanent metal components in theimaging/treatment area of the table top. The accessories can include atleast one selected from the group consisting of tip extension, a headsupport board, a head and neck immobilization board, an x-ray phantom, aleg support board, a brachytherapy stepper assembly and a tip extensionbase stirrup, brachytherapy stepper device, clamps, modular clamps, tipextension base, and drop leaf tip extension. In addition, the design ofthe present table top system allows a table to be constructed that isuniform in carbon fiber skin thickness so that image artifacting isminimized. In addition, the uniform construction also allows for minimumelectron generation when used in high energy radiation therapy.

Furthermore, the present invention provides a method of attachingaccessories that is also compatible with adding accessories to the tipof a sliding beam couch top that does not have a permanent connectionacross the front of the two beams.

The table top and accessories of this invention are designed so that thebest possible imaging and treatment configurations are possible. Withall accessories removed, the table top is completely metal free in thearea of interest.

FIG. 1 shows a table top of the current invention (1). Indexing features(2) are present down either side of the table top. The indexing featuresare commonly used in radiation therapy to locate patient positioningdevices. In this invention, they additionally provide discreet locationsat which clamps may be located. A notch (4) is present on the front edgeof the table top to accept a matting feature present for accuratealignment purposes on the tip accessories. It does not matter whether amale feature or female feature is used on the table top as long as thecorresponding feature is placed on the accessory. The table top ismounted to a base (6) which may be of a static or motion type. In thisconfiguration, the portion of the table top that extends beyond the base(6) is completely metal free.

FIG. 2 shows the tip of the table top from the underside (3). Optionalgrooves (8) are placed longitudinally down either side of the bottomsurface to help with alignment of the accessory clamps.

FIG. 3 demonstrates the free standing Tip Extension Base (10). Aprotrusion (12) is present which mates with the corresponding feature(4) of the table top (shown in FIG. 1). A pair of clamps (14) areintegrated into the Tip Extension Base so that it may be secured oneither edge of the table top. Hanging hooks (16), an alignment pin (20),and a pair of magnets (18) are used to attach extension devices to theTip Extension Base.

FIG. 4 shows the Tip Extension Base securely attached to the front ofthe table top. FIG. 5 shows a quality assurance (QA) phantom (22)attached to the Tip Extension Base (10) which is itself attached to thetable top (1).

FIG. 6 shows a table top (1) with an extension (24). FIG. 7 shows atable top (1) which has a drop leaf extension (28) attached to its tip.This extension can be moved from vertical (26) to horizontal (28) andcan be use to help patients get on the table for brachytherapyprocedures. Two additional clamps (30) are shown on the table. Theclamps contain a section of universal rail (32) which provides anindustry standard method for attaching a variety of accessories,including stirrups.

FIG. 8 shows a table top (1) with a brachytherapy stepper (34) attachedto the tip and two radiolucent stirrups (38) attached to either side ofthe table top. By removing the brachytherapy stepper (34), clear accessis gain to the perineum for imaging, including Cone Beam CT.

FIG. 9 shows a modular clamp with upper (40), middle (42) and lower (44)sections. By changing the middle section (42) a variety of accessoriescan be created efficiently. The center section can be at least oneselected from the group consisting of a universal rail, an arm boardmating component, a tip extension base member, a tip extension member,and a stirrup. The clamp of FIG. 9 contains a middle section (42) whichmounts the universal rail (32). The lower section (44) contains andoptional raised bump (45) which mates with the clamp groove (8) and aidsin securely fastening the clamp to the table top. FIG. 10 demonstrates amethod of creating additional devices by changing the middle section(46) to a new component.

FIGS. 11A and 11B and 12 demonstrate a method which can be used todesign a clamp that can be located at the discreet points of the tableindexing features (2). A circular knob (48) is provided that is machinedin such a way that a locating feature (50) and (52) is present to engagethe table feature (2). When turned 90 degrees, the feature no longerengages the table notch (2) and the clamp is free to be positionedcontinuously down the edge of the table. FIG. (12) shows addition cutaway views of the clamp so that we can see the knob.

In a preferred embodiment, it is preferable that the accessory clampsremain flush or below the top surface of the table top. This embodimentis illustrated in FIG. 13. The edges are recessed (54) so that the uppersection (40) of the clamp remains flush with the top surface (56) of thetable top. This allows other devices to be placed on top of the tabletop without interference from the clamp. The same geometrical treatmentmay also be applied to the front edge (58).

In FIG. 14A it is demonstrated that the same approach of using aremovable Tip Extension Base and clamps can be applied to a table topthat has support beams (60) with modular insert surfaces (62). Beamclamps can be fixed to the back of the tip extension base or slide on alinear bearing way. The support beam cross section (68) is shown in FIG.14(C) with one possible clamp configuration (66) in which a knob (70) isused to tighten the clamp to the support beam. FIG. 14C illustrates asliding beam clamp (63) attached to the tip extension base (64).

1. A radiolucent patient table top system comprising a patient tablewith a front, an underside, at least one side and a mounting supportstructure and further comprising; a. a section which is completely metalfree beyond the mounting support structure; b. the section capable ofreceiving removable accessories; and c. a removable tip extension basewherein the tip extension base provides a universal attachment mechanismwhich allows one or more accessories to be attached to the table.
 2. Thepatient table top system of claim 1 wherein the tip extension base canbe accurately and repeatably aligned with the patient table.
 3. Thepatient table top system of claim 2 which can be aligned by means of atleast one male and at least one female feature, one of which is placedon the front of the table and the other on the tip extension base. 4.The patient table top system of claim 1 wherein the tip extension baseis attached to the table by means of at least one integrated clamp whichattaches to at least one side of the table and the front of the table.5. The patient table top system of claim 1 wherein the one or moreaccessories is at least one selected from the group consisting of alength extension, a head support board, a head and neck immobilizationboard, an x-ray phantom, a leg support board, a brachytherapy stepperassembly and a tip extension base.
 6. The patient table top system ofclaim 1 further comprising a clamp groove which runs along the underside of at least one side of the table and the front of the tablewherein the clamp groove is capable of accepting a mating geometrylocated on a clamp.
 7. The patient table top system of claim 1 furthercomprising discreet indexing features so that the one or moreaccessories can be accurately and repeatably located.
 8. A removablemodular clamp comprising an upper body, a lower body and a modularcenter section.
 9. The removable modular clamp of claim 8 wherein thecenter section is at least one selected from the group consisting of auniversal rail, an arm board mating component, a tip extension basemember, a tip extension member, and a stirrup.
 10. A removable clampcomprising a feature that allows it to be accurately and repeatablylocated to at least one discreet table indexing feature.
 11. A removableclamp comprising an upper body, a lower body and a modular centersection and further comprising a raised bump on the lower body so thatthe clamp can be more firmly affixed to a table top of claim
 6. 12. Aradiolucent patient table with at least one support beam and comprisinga removable tip extension base that has a back face and is attached tothe patient table and wherein the tip extension base provides auniversal attachment mechanism for attaching one or more accessories tothe table.
 13. The patient table of claim 12 wherein the tip extensionbase is attached to the table by at least one integrated clamp thatattaches to the at least one beam.
 14. The patient table of claim 13wherein the at least one clamp can slide laterally on a back face of thetip extension base to accommodate the lateral motion of the supportbeams.
 15. The patient table of claim 12 wherein the accessories is atleast one selected from the group consisting of tip extension, a headsupport board, a head and neck immobilization board, an x-ray phantom, aleg support board, a brachytherapy stepper assembly and a tip extensionbase stirrup, brachytherapy stepper device, clamps, modular clamps, tipextension base, and drop leaf tip extension.
 16. A patient table topsystem of claim 1 wherein at least on of the side and front edges arerecessed, allowing clamps and accessories to remain flush or below thetop surface.
 17. A table top of claim 1 further comprising at least oneradiolucent stirrup attached thereto.
 18. A method of performingbrachytherapy treatment procedures using a table top of claim 1comprising; a. placing legs of a patient in radiolucent stirrups; b.planning imaging and treatment; c. placing a brachytherapy aimingstepper device at the end of the table top; d. inserting a cannula (i)into the patient; e. removing the brachytherapy stepper device; and f.imaging and treating the patient with radiation.
 19. A method oftreating a patient with external beam radiation therapy using a tabletop of claim 1 comprising; a. attaching a tip extension base to a tip ofthe table top; b. attaching an extension to the tip extension base toincrease the length of the table top; c. placing a patient on the tabletop and locating the patient's abdomen over the radiolucent table top;and d. treating the patient.
 20. A method of treating a patient withexternal beam radiation therapy using a table top of claim 1 comprising;a. attaching a tip extension base to a tip of the table top; b.attaching a head and neck treatment device extension to the tipextension base; c. placing a patient on the table top and locating thepatient's head on the head and neck treatment device; and d. treatingthe patient.